2010-11-16 10:00 AM
The way that you access the raw data does not effect the deduplication outcome.
I'd expect slightly worse deduplication results on an iSCSI/FCP LUN depending on the nature of the filesystem being used with it.
2010-11-18 03:30 PM
The deduplication yield is a function of the kind of data being stored on the volume, not the protocol used to access it. The choice between either depends on what you're doing. Personally I try to do everything with NFS and avoid using LUNs where I can for flexibility reasons.